Preparation and Photochromic Behavior of Spiropyran-Containing Fluorinated Polyacrylate Hydrophobic Coatings

In this study, spiropyran (SP)-containing fluorinated polyacrylate (F-PA–SP) latex was prepared by emulsion polymerization using fluorinated and SP-based acrylic monomers as raw materials. Fourier transform infrared and 1H NMR demonstrate that the F-PA–SP copolymer has been successfully synthesized, and dynamic light scattering and transmission electron microscopy analyses indicate that the synthesized latex has presented a uniform particle size of approximately 200 nm. X-ray photoelectron spectroscopy, atomic force microscopy, and water contact angle (WCA) analyses were used to investigate the surface properties of the F-PA–SP coating and demonstrate that its hydrophobicity is enhanced by the addition of a fluorinated acrylic monomer. The photochromic properties of the coating were investigated by UV/vis spectroscopy, and the results reveal that the F-PA–SP coating possesses better photoresponsiveness, fatigue resistance, and photoreversibility under UV/vis irradiation than the coating prepared using fluorinated polyacrylate/SP blended latex. Moreover, the WCA of the F-PA–SP coating subjected to UV/vis irradiation shows minimal changes and retains its excellent hydrophobicity. Finally, the F-PA–SP latex was applied to cellulosic paper, and the resulting photochromic paper exhibits outstanding reversible color changes and hydrophobicity.